Organic delivers greater environmental benefits to plant-based diets

A study of more than 34,000 people has found that diets high in vegetables are better for the planet than animal-based ones but also flagged that organic production systems have “significant” environmental benefits for plant-based diets.

The study, published in journal Frontiers in Nutrition​, is the first of its kind to investigate the environmental impacts of both dietary patterns and farm production systems.

It concluded that while organic food provides large-scale additional climate benefits for plant-based diets, it does not for diets “with only moderate contribution from plant products”​.

What does a ‘sustainable diet’ look like?

Many organisations, including the UN's Food and Agriculture Organisation, advocate the urgent adoption of more sustainable diets at a global level.

This includes reduced consumption of animal products, which have a higher environmental impact than plant-based products due the high energy requirements of livestock farming and contribution to greenhouse gas emissions. Intensive livestock production is also responsible for significant biodiversity loss due to conversion of natural habitats to grass and feed crops.

The method of food production may also influence sustainable diets, the researchers noted. Organic agriculture is generally considered more environmentally friendly than other modern production techniques. However, while many studies have investigated environmentally sustainable diets, these have rarely considered both dietary choices and the production method of the foods consumed.

"We wanted to provide a more comprehensive picture of how different diets impact the environment. In particular, it is of considerable interest to consider the impacts of both plant-based foods and organic foods,"​ explained Louise Seconda from the French environmental agency Agence De L'Environnement Et De La Maitrise De L'Energie and the Nutritional Epidemiology Research Unit, one of the article's authors.

"Combining consumption and farm production data we found that across the board, diet-related environmental impacts were reduced with a plant-based diet -- particularly greenhouse gas emissions. The consumption of organic food added even more environmental benefits for a plant-based diet. In contrast, consumption of organic food did not add significant benefits to diets with high contribution from animal products and only moderate contribution from plant products,”​ she continued.

How did they calculate it?

The investigation utilised information on food intake and organic food consumption from more than 34,000 French adults. The researchers used what's called a 'provegetarian' score to determine preferences for plant-based or animal-based food products. They also conducted production life cycle environmental impact assessments at the farm level against three environmental indicators: greenhouse gas emissions, cumulative energy demand and land occupation.

The authors suggested it will be important to conduct further studies to confirm these results and to expand our understanding of how the entire food production lifecycle impacts sustainability.

The researchers also flagged that the environmental effects of production systems are not uniform and can be impacted by climate, soil types and farm management.

"We didn't look at other indicators such as pesticide use, leaching and soil quality which are relevant to the environmental impacts of productions systems,"​ noted Seconda. "Therefore future studies could also consider these as well as supply chain and distribution impacts of food production."​